Not necessarily. It depends on what the allergen is and what the reaction is. There's no reason to worry about a reaction that hasn't happened yet.

Not allergies are like peanut allergy. A severe reaction doesn't have to be throat closing or hives.

For instance, I am sensitive (allergic my allergist calls it) to sulfites. My reaction to that can start in a half hour to 2 hours. I don't get swelling in the throat, but I do get tachycardia, which once triggered a heart attack and has sent me to the hospital a few times.

Or, my allergy/sensitivity to albuterol - which started 8 hours after I inhaled a puff and put me in the hospital.

A severe allergy can happen the first time you come in contact with the allergen, or the second, or even after years.

Do you have a particular reaction? Do you think you may be allergic to something?

I never had a severe reaction. I only react by itchy eyes , watery nose sneezing from seasonal allergies. But since I suffer with anxiety. I keep thinking I'm going to have an anaphylaxis reaction to foods, nuts etc. so I was wondering if the reaction (anaphylaxis ) would happen right away or hours after ingesting ?Suffer with anxiety and panic attacksMeds: celexa 20 mg and clonasapam 0.5 mg